Looking for fitness information

[Dangerscouse]

But watts and watt-seconds (joules) are of interest, right? 4.2 joules = 1 calorie. Both are formally defined measures the same thing: work or energy. Like you, I don't care about how much food energy is burned; if I did I would try to measure it more accurately.

I care about the work done in a workout. The current PM is adequate for calculating overall work: average watts times time in seconds gives work in joules. Divide by 4.2 to get work in calories. I just wish it would do one of these instead of the [food] Calorie estimate.

To be honest, I only ever row using pace, so any other measure isn't of interest. Watts could be useful, but I've got so much background info for pace, that I just keep it simple.

I like that there are different options, as we are all different, but it's superfluous for me. That might be because I don't ever calorie count, and I seem to have found a happy balance of work, and calorie intake as I only put weight on if I don't row for a notable time. I only put a very small amount of weight on recently, despite reducing my overall weekly distance by about 40% for three months as I recovered from long Covid.

[frankencrank]

I think you are in the wrong thread.

What makes C2 not a true ergometer is they don't account for the work done overcoming the shock cord. It would be very easy to do but they chose not to. What makes it valuable as a "scientific" training tool is output is repeatable and self calibrating.

I didn't know there were right and wrong threads. I was responding to a comment in this thread. I'd be happy enough to see the discussion in another.

The C2 PM(x) measures work delivered to the flywheel. It does not measure all mechanical work done by the body. I don't see why that makes it "not a true ergometer."

The C2 apparently doesn't account for losses in the bungee cord, or losses in the chain or the seat/rail, or recovery. In other words, it measures work delivered to the flywheel. The cord/chain/rail losses pale compared to recovery.

I suggest "reliable" is a better word than "<quote>scientific<unquote>"

I apologize but I couldn't find what you were responding to. I have responded to wrong threads or the wrong person before. It is all good.

[frankencrank]

My calories probably won't be yours in real life: a key element in the calculation underpinning 300 calories should be the persons weight. But then again: most people don't make a big deal out of it.

If we're talking about work applied to the flywheel, my calorie = your calorie = 4.2 joules = 4.2 newton-metres = 0.004 BTU.

By convention, Americans measure food energy in Calories (i.e. Kcal). I'm not interested in how much food energy I'm consuming. I'm interested in how much work I'm doing. Clearly food energy will be something larger than that, because neither my body nor the equipment is 100% efficient. How much larger is anybody's guess, and I don't want that guess built into my exercise equipment.

Work applied to the flywheel is one thing. Calories expended is another. weight will play a smaller role on a rower compared to running for instance. Technique can also affect efficiency, as I have mentioned in another thread.

[frankencrank]

I will accept I made an error when I said CO increased 20 times when I meant Oxygen delivery increased 20 times. It is the interweb and my editor is on vacation. Your problem is your intent is to belittle me

Initially I simply asked if you really meant CO since your values were so extreme. You doubled and then tripled down on CO, so don’t throw your “editor” under the bus. My “problem” is that you belittle anyone else’s understanding of physiology because they don’t have your background.

People, even I, sometimes get confused. CO goes to 20, Oxygen consumption increases 20 times. I didn't see what you were trying to transmit initially because of that internal confusion in my little pea brain. One of the advantages of posting things on the inter web is weaknesses in thought are, usually, quickly pointed out. What you pointed out, that I initially missed, was a weakness in my explanation. I still see no major weakness in my approach.

I guess you are presuming my cardiologist doesn't know what he is doing when he reported to my the mets I achieved on my stress test.

I didn’t presume anything because you provided the details. Your cardiologist knew what he was doing when he told you your heart responded well under stress (the purpose of the test) but he only estimated your METs (not the purpose of the test) and you don’t know the details of how the estimate was made. So you’re in good shape, and are reasonably confident you can push yourself on your own. Mission accomplished.

Are you saying my doctors estimate of my mets was nothing more than a guess? Are you saying all those tables available on the inter web detailing various mets levels to different exercise intensities are also just guesses?
https://www.acefitness.org/resources/pr ... uivalents/

I am comfortable Apple Watch is assessing me wrongly. I am curious as to why and how can it be corrected. If you don't care, go on with your life. Ignorance is bliss.

Good. You have come to terms with it after being “really bothered” two days ago. I might enjoy the challenge of solving a physiological puzzle under different circumstances, but clearly this isn’t the time or place. This is my last response in this thread. Good luck with your quest.

While you don't care, I have come to believe that as a screening tool, it is not necessary to know the anaerobic threshold to do this evaluation. The assessment will be better if one knows this but most people don't have a clue what that is so how to assess them.

Anyhow, it is clear I am probably not going to get any data to help me assess my algorithm here so I will probably stop asking anymore.

[JaapvanE]

While you don't care, I have come to believe that as a screening tool, it is not necessary to know the anaerobic threshold to do this evaluation. The assessment will be better if one knows this but most people don't have a clue what that is so how to assess them.

So you want people to move for 10 minutes, without any clear criterion how intensive it should be and under which specific conditions, and than make medical decisions based on their heartrate? Why not just take a bunch of dice?

[frankencrank]

While you don't care, I have come to believe that as a screening tool, it is not necessary to know the anaerobic threshold to do this evaluation. The assessment will be better if one knows this but most people don't have a clue what that is so how to assess them.

So you want people to move for 10 minutes, without any clear criterion how intensive it should be and under which specific conditions, and than make medical decisions based on their heartrate? Why not just take a bunch of dice?

Actually, as I posted above, I, now, don't think it is necessary for them to move at all to make reasonable conjectures as to their risk due to fitness issues. The "moving" part would just improve the association and make the decision a bit less of that "guess." But, no one here seems to understand nor care so be it.

[gvcormac]

I think you are in the wrong thread.

What makes C2 not a true ergometer is they don't account for the work done overcoming the shock cord. It would be very easy to do but they chose not to. What makes it valuable as a "scientific" training tool is output is repeatable and self calibrating.

I didn't know there were right and wrong threads. I was responding to a comment in this thread. I'd be happy enough to see the discussion in another.

The C2 PM(x) measures work delivered to the flywheel. It does not measure all mechanical work done by the body. I don't see why that makes it "not a true ergometer."

The C2 apparently doesn't account for losses in the bungee cord, or losses in the chain or the seat/rail, or recovery. In other words, it measures work delivered to the flywheel. The cord/chain/rail losses pale compared to recovery.

I suggest "reliable" is a better word than "<quote>scientific<unquote>"

I apologize but I couldn't find what you were responding to. I have responded to wrong threads or the wrong person before. It is all good.

Umm. I quoted your use of the word "scientific" in scare quotes.

[frankencrank]

I didn't know there were right and wrong threads. I was responding to a comment in this thread. I'd be happy enough to see the discussion in another.

The C2 PM(x) measures work delivered to the flywheel. It does not measure all mechanical work done by the body. I don't see why that makes it "not a true ergometer."

The C2 apparently doesn't account for losses in the bungee cord, or losses in the chain or the seat/rail, or recovery. In other words, it measures work delivered to the flywheel. The cord/chain/rail losses pale compared to recovery.

I suggest "reliable" is a better word than "<quote>scientific<unquote>"

I apologize but I couldn't find what you were responding to. I have responded to wrong threads or the wrong person before. It is all good.

Umm. I quoted your use of the word "scientific" in scare quotes.

The use of the term "scientific" referred to the "fact" that "it seems" to be the go to rowing ergometer for published studies. You know, science.

[gvcormac]

The use of the term "scientific" referred to the "fact" that "it seems" to be the go to rowing ergometer for published studies. You know, science.

Well, it is one of the most available and understood instruments for measuring net mechanical energy output. So I would not be suprised if it was commonly used in scientific studies. If it is used to measure gross metabolic energy consumption, that's a mistake. Do some studies make that mistake?

I have difficulty understanding the points you are making. Are you saying that you want to assess fitness (and health outcomes) by comparing metabolic energy consumption to physical work achieved? Could you explain concisely what predictor and outcome variables you're planning to assess?

[frankencrank]

The use of the term "scientific" referred to the "fact" that "it seems" to be the go to rowing ergometer for published studies. You know, science.

Well, it is one of the most available and understood instruments for measuring net mechanical energy output. So I would not be suprised if it was commonly used in scientific studies. If it is used to measure gross metabolic energy consumption, that's a mistake. Do some studies make that mistake?

There are tons of mistakes in scientific studies even with peer review. But, measuring gross metabolic activity is usually done by actually measuring oxygen uptake and the respiratory quotient.

I have difficulty understanding the points you are making. Are you saying that you want to assess fitness (and health outcomes) by comparing metabolic energy consumption to physical work achieved? Could you explain concisely what predictor and outcome variables you're planning to assess?

What I think can be done is to look at some readily available physical parameters (resting HR, sustainable exercise HR, age) and make an assessment of that persons relative aerobic fitness which can then be compared to some cardiac risk data. I was looking for some data that, I suspect, some here have so I could get a sense if I was on to something or my methods need tweaking.

[JaapvanE]

What I think can be done is to look at some readily available physical parameters (resting HR, sustainable exercise HR, age) and make an assessment of that persons relative aerobic fitness which can then be compared to some cardiac risk data. I was looking for some data that, I suspect, some here have so I could get a sense if I was on to something or my methods need tweaking.

A parameter gaining traction is Heart Recovery Rate: the difference in HR one minute (HRR1), two minutes (HRR2) and three minutes (HRR3) after an excercise. There are some decent correlations in this metric with heart dissease and all type morbidity when used in a maximum heart rate excercise, but some correlations seem to hold when you end the excercise in a HR Zone 3 (70% of Max HR). Some debate is still around what stressor to use exactly (for example, is it reliable when it is a sustained long HR zone 3 excercise?) and when a difference is considered deviating.

You can find a very decent meta-analysis here (open access): https://www.ahajournals.org/doi/10.1161/JAHA.117.005505

Their analysis is so compelling that I consider adding HRR1 and HRR2 as additional set of measurements to Open Rowing Monitor (we already have the key ingredients to our disposal for the VO2Max calculation).

[gvcormac]

JaapvanE: Does your Open Rowing Monitor support equipment like bikes that don't have a periodic coast? The C2 Bike Erg uses a hack to calibrate for damper position, based on an enforced coast-down. I wonder what one might do, for example, with my elliptical. I could probably put a sensor on the flywheel, but there's never a coast-down. Maybe I could jump off the pedals but ... . Spin bikes and "air bikes" would have the same problem.

[JaapvanE]

JaapvanE: Does your Open Rowing Monitor support equipment like bikes that don't have a periodic coast? The C2 Bike Erg uses a hack to calibrate for damper position, based on an enforced coast-down. I wonder what one might do, for example, with my elliptical. I could probably put a sensor on the flywheel, but there's never a coast-down. Maybe I could jump off the pedals but ... . Spin bikes and "air bikes" would have the same problem.

The thing is that the coast-down provides an interesting moment: the only force is the dragforce, and thus you can measure drag. But we are capable of measuring it once, and then it could be recorded in the settings (we have an option that blocks the automatic calculation of the drag force). I guess that is what C2 does with their bike in a nicer way: you "callibrate" once, and then they fixed the drag factor.

Some key metrics like time and distance aren't dependent on detecting strokes, so they keep going regardless of the stroke counter. The power and force metrics are stroke dependent, so they wouldn't be calculated. But with some modification, it could work. The big challenge is that some underlying assumptions are different: for example the power calculation on a rower is based on the assumption that only work is done during the drive phase, whereas on a bike, you keep putting power in.

[gvcormac]

JaapvanE: Does your Open Rowing Monitor support equipment like bikes that don't have a periodic coast? The C2 Bike Erg uses a hack to calibrate for damper position, based on an enforced coast-down. I wonder what one might do, for example, with my elliptical. I could probably put a sensor on the flywheel, but there's never a coast-down. Maybe I could jump off the pedals but ... . Spin bikes and "air bikes" would have the same problem.

OK, I can spin my elliptical using the handle only while standing on the floor and then let go. I imagine I could do this for a number of resistance settings, but for the high ones not at a particularly high speed. I suppose it would be possible to extrapolate given a model of the magnetic resistance.

I guess you could do that on a spin bike as well. I have managed to pass the calibration procedure on my C2 Bike Erg working the pedal by hand.

I really think I might use my elliptical as something other than a coat rack if I could make it into an erg.

[gvcormac]

The thing is that the coast-down provides an interesting moment: the only force is the dragforce, and thus you can measure drag. But we are capable of measuring it once, and then it could be recorded in the settings (we have an option that blocks the automatic calculation of the drag force). I guess that is what C2 does with their bike in a nicer way: you "callibrate" once, and then they fixed the drag factor.

Some key metrics like time and distance aren't dependent on detecting strokes, so they keep going regardless of the stroke counter. The power and force metrics are stroke dependent, so they wouldn't be calculated. But with some modification, it could work. The big challenge is that some underlying assumptions are different: for example the power calculation on a rower is based on the assumption that only work is done during the drive phase, whereas on a bike, you keep putting power in.

C2 sense the damper setting, so they don't quite fix the drag factor; they fix a calibration curve. But for my elliptical, I'd have no way of sensing the resistance setting so would presumably have to live with a fixed drag factor.

I'm not sure why power and force are stroke dependent. I suppose those have special meaning in the rowing community.

Based on what you've said, I might try on my elliptical. I have a Pi. What sort of sensor do I need? Optical would be the easiest, I guess.